Fulton school officials reported Wednesday a middle school student "intentionally harmed" two other students with a small knife on the campus.
No names were given as the students involved are juveniles.
"My understanding was that there was no provocation," Superintendent Jacque Cowherd said Wednesday evening.
Cowherd added as far as he knows, there were no warning signs. He and other administrators will discuss the situation in a meeting today.
A notice went out to parents of students at 3:40 p.m. Wednesday to alert them of the event, according to spokeswoman Karen Snethen.
Two victims, aged 11 and 12, were treated by the school nurse, and their parents were contacted, the notice stated.
"They chose to leave the students at school," Cowherd said.
The wounds the students received were minor, officials said.
Cowherd said administrators at the school reacted according to protocol. The attack took place in a classroom, he said, and students in other classrooms remained in place until the incident was over.
The perpetrator was taken into police custody, Snethen added.
"I haven't yet talked to the police about what level of assault this would be," Cowherd said.
School policy states the consequences for assault range from parent-teacher conferences up to expulsion.
"It is believed that several non-involved students were aware the perpetrator was in possession of the small knife," the notice also stated.
Cowherd encouraged students to tell an adult if they suspect a student may have a weapon or may plan to harm others.
"If we had been told about the knife and found it, this wouldn't have happened," he said.
While this is the only reported assault with a weapon at a Fulton school during the 2016-17 school year, it isn't the first time a student has shown up with a weapon.
Cowherd mentioned an elementary student brought a pocket knife to school in his backpack in the fall, having apparently forgotten to remove it after a hunting trip. In October, a student at Bush Elementary was disciplined for bringing a BB gun to campus. No students were injured in either event.
"I believe we have a safe school," Cowherd said.